Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Natural time capsule containing an alien ecosystem.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The magic's in the hole!

Beyond being incredibly fun, not much can be said about the Hole with certitude.

The longest continuous lava tube in Oregon.

An oil baron's wild paradise and the winner of an ill-fated air race.

A whimsical tower with a spiral staircase, inspired by the Space Age and the Möbius strip.

A wonderful collection of all things Oz is nestled in the heart of Kansas.

A landscape of massive spherical boulders are the main attraction in this Kansas State Park.

The United States's largest hand-dug well is topped with a state-of-the-art museum.